setting up expo on a warbird ?
 

Yes as crazy as it seems I never set up expo on any of my warbirds . After reading a magazine article recently I think I am really missing a great radio asset .
On the Spectrum 7 I know the + means less sensitivity , my question is , is there a right formula for warbirds ? Will expo be differant on one flight surface vs another ?
Thanks

RE: setting up expo on a warbird ?
 

On conventional planes I don't see a reason to use it all of the time. Sometimes on larger aerobatic models I'll put in a little expo on the elevator and ailerons but then take it out after several flights once I've gotten familiar with how it flies. To me it just makes control feel "mushy" and I'd rather "fly" the plane.
On certain planes with elevons and small/fast /darty planes I leave a little expo in.
To each his own I guess.

RE: setting up expo on a warbird ?
 

Brian , thanks for the comments and I know all about flying without expo . I was told that on warbirds ( that I fly often) then can reduce the twitchy over-control .
I sincerely appreciate your comment but I am more interested in warbirds and expo , the wing loading and low wing is typically not what you will see on a sport plane or a warbird defined as a sport plane that has light wing loading .
Thank you

RE: setting up expo on a warbird ?
 

Here's the deal.

Put it on a switch and try it.

Your plane won't explode in mid air. If you don't like it turn it off, land, and 0 it out.

Typically I do about 20 percent on ailerons and rudder and 25 to 30 on the elevator for such a plane but it's completely about personal feel, there is no magic formula.

If you're used to no expo, much more than that will make it feel mushy though.

FWIW to get linear throw, because a round servo output is non-linear, you need 18 to 22 percent anyways, otherwise you're already getting reversed expo (more sensitive at center)

RE: setting up expo on a warbird ?
 

Thanks that is exactly what I was looking for !

RE: setting up expo on a warbird ?
 

I start at 30% on all my planes and adjust from there, once you start using it and find the % that right for you,, your freinds will comment on how smoothly you fly...

It's there,, try it and see if you like it ;)

RE: setting up expo on a warbird ?
 

Use 30% on the ailerons and elevators. If you use a "Y" connector for them you will get the same expo on each surface. If you are using different channels for each one it may be dependent on your radio. Dan.

RE: setting up expo on a warbird ?
 

I have the elevators on my warbirds set up on dual rates, one for landing, one for the rest of the flight. The landing setting has the 100% throw and (about) 20% expo. Other flight condition generally has something like 80% throw and (about) 30% expo. Ailerons/rudders are on a different switch, but I don't usually adjust them for flight conditions.<div>
</div><div>I did run across a situation on my TF GS Mustang (actual plane and simulator) where I had 40% or more expo for landing. It seemed to get elevator sensitive just before touchdown. Reducing the expo to 20% and increasing the elevator travel seem to tame it down. I think it was sensitive because with the original elevator travel during landing I was adding elevator and got out of the low response expo range into the higher response range. </div><div>
</div><div>Brian</div>

RE: setting up expo on a warbird ?
 

Sorry, but computer radios put expo on the function, not the individual servo.

If there's any radios that are otherwise, please let me know which, because in my somewhat admittedly limited experience, I've yet to have seen one.

RE: setting up expo on a warbird ?
 

This is a subject that I have heard a lot of discussion on.
Basically, in my opinion, there is no solid answer that is correct for each plane/pilot/radio combination.
There are too many variables to consider to make this a simple answer.
The FIRST order of business is to make sure you have the plane setup properly.
Starting with making sure you are happy with the center of gravity and including proper setup of the geometry of the various control linkages.
Only after you have fine tuned these as part of your preliminary test flights, should you then go ahead and start using the computer radios various tweaks.

RE: setting up expo on a warbird ?
 

I set all my planes with -30% on all functions to start (futaba is opposite of JR so it's the same a +30% on JR)

Most or the time I'm happy with that.... but if I have a tail wheel or rudder that is sensitive I will go up on that.

I fly warbirds on low throws and land with high throws with more expo.... helps me not run out of rudder or elevator on landing but the lower throws make the plane smoother in flight. At time I will go to high in flight for rolls or some rank and bank

there is no right answer and this subject it's all about each persons feel

RE: setting up expo on a warbird ?
 

Thanks guys , all great comments . I have flown this particular plane with no expo but its not fun and twitchy. The CG is at 25% of mac and that is for all my planes . Ailerons are way to sensitive , elevator is fine no real issues , same with rudder .
Thanks for the tips and your patience .
i am going to start at 30% and get a feel

RE: setting up expo on a warbird ?
 

Have you tried moving out at the horns or in on the servo arms. Or maybe even both?
Get the mechanical right before you start making electronic adjustments.

RE: setting up expo on a warbird ?
 

Your ailerons are too sensitive. Is there ever a situation where you would want the full throw that you have available? If not, reduce the throw by moving the pushrod in on the servo arm or out on the control horn (best) or reducing the end points on that channel (acceptable).

You should never have more total throw than you can safely use on any channel. Set the maximum throw on the ailerons to your highest comfortable roll rate and the maximum throw on the elevator at just less than whatever causes an uncommanded snap roll at the top of a loop. Do this mechanically, if possible, not in the transmitter. Then if you still need to soften the controls, use expo.

Jim

RE: setting up expo on a warbird ?
 

Yeah, what he said.

RE: setting up expo on a warbird ?
 

yes the ailerons are set at a moderate position , everything else is in check , I even suspect a nose heavy situation based on needing up elevator in normal turns but that was resolved .

RE: setting up expo on a warbird ?
 

For years I did not use expo and at times I would give too much elevator when landing and have the plane balloon up (very dangerous on a heavy war bird). I now use just a little on my elevator (15%) and I have very smooth landings. I also use 10% on my ailerons and my flights are seem smoother. My fellow flyers tell I should use more but I also find with too much the controls seem mushy.
P51Tom

RE: setting up expo on a warbird ?
 

Do whatever you like, personally I don't use expo at all. As a scale flyer for many years my thumbs came with expo.
Larry

RE: setting up expo on a warbird ?
 

Flying is always a personal choice. As such do what ever you are comfortable with. If you like Expo use it. I do and have for a long time. Some do and some don't. Not everyone is the same ...:)

RE: setting up expo on a warbird ?
 

Lou,
on my 42lb Seafury I use about 30% expo on elevators and on ailerons. I find it smooths the flight reigme and make it more scale like. Rudder I leave without expo nomally as I need it very responsive on the take off roll, I rarely use rudder in flight unless I am doing a wingover after a climb.

Best trick it to dial in a small amount, say 10%, try and see how it feels. Keeps going up in 10% increments till you find that happy balance.

cheers
P

RE: setting up expo on a warbird ?
 

I never liked using expo until a racing buddy directed me to try it with my pylon planes. Once I got used to it, I really like it. I will be the high bidder here as I use around 45%. I worked up to this number though. I think if you started out with this much, the controls would feel scary sluggish at first.

A surface where it is really nice is on rudder. I fly a lot of WW1 scale, and it really helps to keep things calm on takeoff.

RE: setting up expo on a warbird ?
 

I have always used expo on my war birds. I build scale, and like my planes to look scale in the air as well. Yes, they may feel "mushy" as one person said, but that is the look I'm going for in a heavy metal war bird. I especially like the realistic take-off rolls I can get with about 70% expo in the rudder. I'm never 'chasing' the rudder on the take-off roll, so the plane is NEVER whipping back and forth as it builds speed. This is one part of the flight that so many models really look like models. My plane tracks smooth as the full scale would, and when it is up to flying speed, I make a gradual assent trying to resist the model like 'leap' into the air. With at least 30% in the elevator and ailerons, smooth maneuvers are easy for me, even in unpredictable wind.

In competition, I use 50 to 60% on the ailerons and elevator, and 70 to 80% on the rudder, (which I use a lot, as in full scale). Depending on the weight of the plane. In combination with this, I set the travel to a high rate. This way, I have extra movement if I need it, and that soft center for smooth control, all without the distraction of flipping switches.

It really is all in what you get used to. I'm living proof. I fly with a reversed elevator!!!! Back in 1969, when I set up my first radio, I set the elevator for up stick is up, and down is down. I have flown that way ever since. Feels perfectly natural to pull back it go up in a full scale, but when I fly RC, I push forward. A side benefit is, and I suspect it is because of my full scale experience, but I am perfectly comfortable inverted, pulling back that is.

I have seen some great pilots, like Dino Digorgio, fly with little or no expo in competition, and do it in a most realistic and scale manor. So I'm not saying it is a must, but it works for me. It may help you as well. Best thing to do is just try it on for size. You just get used to moving your sticks farther.

RE: setting up expo on a warbird ?
 

My experience with expo has been great. Past 5 warbirds I have settled on ( negatives for Futaba) 12 rudder, 24 ailerons, 30 for elevator as my starting points and they seam about right. Good rudder response and smoother flights and landings with expo. Others in our club use 40 on elev but it just felt too soft for me. Give it a try. R, mike

RE: setting up expo on a warbird ?
 

I just wanted to say that just because I use expo doesn't mean I don't set up mechanical right first.

I like to be out towards the end of the control surface horn and as close to the servo I can get on the servo side and still get the throw needed for high rates.... that gives your servo mechanical advantage. I then set all my throws by the book to start.... but still add -30% expo to all surfaces. After maiden I adjust the throws and expo to what feel right for me

To me the plane just feels so much more locked in and really so at high speed with expo..... for my jets it's a must

RE: setting up expo on a warbird ?
 

I agree with TG. Get the mechanical side of the control loop better and then trim it with electronics.

To take maximum advantage of today's radios I drive the servos at about 140% travel. This simple capability lets the servos drive with nearly maximum resolution (particularly important for analog servos). Then I use extra long horns on the surfaces to smoothen out the response (these are +1/2" or so from standard). Then add expo as needed to get silky output response for my type of flying